This work shows the results of a bauxite drying process using microwave oven. In this research the influence of initial humidity, mass and granulometric distribution of bauxite samples were studied. To determine the humidity influence two bauxite samples having 6,9% and 12,2% of humidity were utilized and for the mass and granulometric distribution the sample initial humidity was 13%. The results show that the optimum drying time by microwave has a directly correlation with the initial humidity. The sample mass and the drying time are also directly proportional with a very high correlation. The study suggests that the drying time can be obtained considering the mass of the bauxite sample.